Bug in new demo

[encocan]

const x = 'a';

const y = () => {
    const x = 'b';
    
    console.log(x);
}

y();

Output is right in the demo online ('b'), but when I build the code, the demo output is 'a'.

Thought I would let you know.

[encocan]

@basicer The latest version now has a different error:

> yarn repl
yarn run v1.19.2
$ node contrib/cli.js -i
js> const x = 'a';
UndefinedValue { serial: 0 }
js> const y = () => { const x = 'b'; console.log(x); }
UndefinedValue { serial: 0 }
js> y();
SyntaxError: Identifier 'x' has already been declared
    at VariableDeclaration (<src>:1:18)
    at y(...) (<src>:1:0)